In general, in the Internet, a transmission bandwidth is not always guaranteed between two communicating terminals, but data is transmitted and received while a transmission bandwidth is dynamically occupied in unit of packet.
For the above reason, the communication quality is not guaranteed to a certain level, and packet loss or delay occurs according to communication conditions, thereby being capable of deteriorating the quality of a call.
Meanwhile, the Internet requires a bandwidth 5 to 10 times greater than a bandwidth for voice communication in order to transmit and receive image data in good quality and may have very poor video communication quality if, the requirement is not satisfied. In video communication, a function of controlling a transmission bandwidth is very important. Accordingly, a video terminal must previously set a transmission bandwidth to be used for video communication and must be able to transmit and receive video based on the set transmission bandwidth. This method, however, is disadvantageous in that a transmission bandwidth, dynamically varying during communication, is difficult to deal with.
FIG. 1 is a diagram illustrating a conventional method of measuring a transmission bandwidth.
Referring to FIG. 1, a server transmits two or more proving packets to a reception apparatus at step S110.
Here, the server transmits the proving packets, including a transmission time stamp, to the reception apparatus.
The reception apparatus receives the proving packets including the time stamp of a transmitted time, finds a reception interval between the two received packets, and calculates a transmission bandwidth on the basis of the reception interval at step S120.
Next, the reception apparatus transmits the calculated transmission bandwidth to the server at step S130.
The server streams multimedia data on the reception apparatus by using the transmission bandwidth received from the reception apparatus at step S140.
As described above, the conventional method of measuring a transmission bandwidth is problematic in that it requires the process of the server transmitting the proving packets to the reception apparatus and checking a result apart from transmission data.
Furthermore, the conventional method is problematic in that it occupies an additional transmission bandwidth for transmitting proving packets because it transmits the proving packets apart from transmission data.